It has long been desirable to have a removable auxiliary lens assembly attached to eyeglasses. Professional baseball players have used “flip-up” auxiliary lenses for more than four decades to protect their eyes from the sun, but to allow them unrestricted vision in the event the ball was hit in their vicinity.
U.S. Pat. No. 3,252,747 to Robins discloses an eyewear system specifically designed for persons who are far-sighted. The device includes an assembly in which an auxiliary frame assembly containing lenses may be rotated about the horizontal axis and remain attached to a primary assembly so as to locate the lenses the proper distance to the eyes every time the device is lowered into place. A significant disadvantage of this design is that it is unattractive, overly complicated, impossible to segregate from the primary frame, and does not accommodate anyone other than far-sighted individuals.
U.S. Pat. No. 6,089,708 to Ku discloses a connecting member having spaced connecting plates for attachment to the bridge portion of a primary lens assembly. The connecting plates have magnetic members that act cooperatively with a complimentary magnetic member inserted in a hole on the bridge. The front of the connecting part has an open communication to a polygonal-shaped holding room. The auxiliary frame has connecting rods extending above the bridge portion, and supporting an intermediate portion having a polygonal shape, receivable and rotatable in the holding room. A significant disadvantage of this design is that it is unattractive, overly complicated, and resists easy and immediate removal of the auxiliary lens assembly.
U.S. Pat. No. 3,238,005 to Petitto discloses the combination of a primary lens assembly and auxiliary lens assembly. The auxiliary assembly has flexible side wall projections with openings that can be assembled onto lugs (pins) extending perpendicularly from the sides of the primary assembly, allowing the auxiliary assembly to be pivoted upwards, and back downwards. Leaf springs mounted on the auxiliary assembly engage surfaces of the primary assembly to urge the auxiliary assembly into position. A significant disadvantage of this design is that it is unattractive, overly complicated, and resists easy and immediate removal of the auxiliary lens assembly.
As stated, these and other mechanically clipped on devices for holding auxiliary lenses are cumbersome and unattractive. More recently, numerous attempts have been made to magnetically attach an auxiliary lens assembly to a primary lens assembly.
U.S. Pat. No. 4,070,103 to Meeker discloses a primary lens assembly having a slidably attachable auxiliary lens assembly. In this device, the primary lens assembly is made of magnetizable material and auxiliary lenses are individually securable to the primary lens assembly by a magnetic band inserted in a groove on the inside surface of the individual auxiliary lens assembly. This design is not pivotal, and the auxiliary assembly must be physically removed.
U.S. Pat. No. 5,416,537 to Sadler discloses a primary lens assembly having a first magnetic member attached vertically to the front surface of the primary lens assembly, and a second magnetic member attached in a corresponding position on the back surface on an auxiliary lens assembly. The magnetic members are arranged for engagement to secure the auxiliary lens assembly to the primary lens assembly. This design is not pivotal, and the auxiliary assembly must be physically removed.
U.S. Pat. No. 5,568,207 to Chao also discloses a magnetically adhered auxiliary lens assembly, with the additional feature of arms extending from the side portions of the auxiliary lens assembly, over magnet retaining projections and extensions of the primary lens assembly. The arms engage with, and are supported on, the primary lens assembly extensions to prevent disengagement of the auxiliary lens assembly upon downward movement of the auxiliary lens assembly relative to the primary lens assembly. This design is not pivotal, and the auxiliary assembly must be physically removed.
Auxiliary eyewear systems such as those described above require the auxiliary frame assembly be removed from the primary frame assembly, and then handled and stored separately when it is necessary for the eyeglass wearer to look only through the lenses of the primary frame assembly. They do not enjoy the advantages of the early flip-up designs, which permitted quick movement of the auxiliary assembly out of alignment with the primary assembly without separating them from the primary assembly.
U.S. Pat. No. 6,474,811 to Liu discloses a magnetically attached auxiliary lens assembly in which the auxiliary assembly can be magnetically attached to the either the inside or outside of extensions having magnets on the primary assembly. The auxiliary assembly is pivotal upwards, removing the pivotal alignment of the auxiliary and primary lenses. A significant disadvantage of this design is that it is unstable, relying on tenuous repositioning, and magnetic forces alone to align and support the auxiliary assembly relative to the primary assembly. Another significant disadvantage of this design is that causes the auxiliary frame to be positioned into the forehead of the wearer, making raising the auxiliary assembly fully perpendicular to the primary assembly impractical.
U.S. Pat. No. 6,301,953 to Xiao discloses an auxiliary lens assembly having pivots mounted above the lenses and attached by long, L-shaped shelter arms. The shelter arms are attached to supporting arms having magnet holding housings attached at their ends. Magnets are inset in the housings for engagement over rearwardly protruding rim lockers. One disadvantage of this design is that it is fails to limit the rotation of the auxiliary lens assembly. Another disadvantage is that it is esthetically unappealing, due in part to the long shelter arm requirement. Another disadvantage is that it relies on a bridge magnet or bride hook for stability. Another disadvantage is that the device relies on magnetic force to pull the magnetic housing forward, over a rearward protruding lens locker, requiring the user push the auxiliary frame awkwardly rearward, into the primary frame, to disengage the magnetic housing from over the lens locker. Another disadvantage is that the device is complex and expensive to manufacture.
An improvement to these designs is disclosed in a co-owned and co-pending U.S. patent application entitled “Rotatable And Removable Auxiliary Eyewear System With Snap Alignment.” The application discloses an auxiliary eyewear support system that utilizes pivotal hinges integral to the auxiliary frame, which permit rotation of the auxiliary frame from a first position in which the auxiliary lenses are substantially parallel to the primary frame lenses, to a second position in which the auxiliary frame assembly is flipped up substantially perpendicular to the orientation of the primary frame assembly.
Each of these systems discloses a primary frame that has a single function attachment means for attaching a singular style of auxiliary lens assembly. In addition, most of these designs require a lens that is limited in width, so as to accommodate the attachment apparatus outside of the mechanism securing the lens to the frame. As a result, peripheral vision through the lens is limited. This can give rise to both convenience and safety issues. For example, a nearsighted person trying to change lanes on a freeway is forced to rotate their head significantly further around to allow alignment of their eye through their lens in the direction of the vehicle blind-spot. These processes increase the time required to affect the maneuver, and requires and increased time in which the direction in which the car is traveling at high speed is not visible. Problems occur again when trying to back-up a vehicle.
In addition to auxiliary lens assemblies, it is often convenient to attach tethers, or chords, to a primary lens assembly to allow for temporary removal of the assembly, without the need to set them down or hold them. It is always required to provide an attachment means to the end of the chord to secure it to the eyeglass assembly.
It can thus be seen that there is a need to develop a design for a primary lens assembly in which the primary frame assembly can be adapted to accept multiple styles of attachable auxiliary lens assemblies. There is also a need to provide such a device that permits insertion of wider lenses to improve peripheral vision. There is also a need to simplify the structure and assembly of primary lens assemblies. There is also a need to provide a primary lens assembly that is easily attachable to a chord that is not specially configured at its ends.